Roller window shade construction



Dec. 13, 1938. E; L, GRAUEL 2,140,049

. ROLLER WINDOW SHADE CONSTRUCTION 7 Filed March 21, 1938 2 Sheets-Sheet l INVENTOR. BY Eon 0v 1.. $1M 051..

ATTORNEYS.

Mq- QM Dec. 13, 1938. .E, L. GRAUE L ROLLER WINDOW SHADE CONSTRUCTION Filed March 21, 1938 2 Sheets-Sheet 2 mvsmox [aw/1v L. Game/4.

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Patented Dec. 13, 1938 UNITED STATES PATENT OFFICE ROLLER WINDOW SHADE CONSTRUCTION Edwin L. Grauel, Cincinnati, Ohio Application March 21, 1938, Serial No. 197,205

3 Claims.

in the separate slotted webs are joined together and so-constructed that desired lighting effects may be obtained in a window opening.

Another object of my invention is the provision of a double webbed shade or blind wherein the webs assume a parallel spaced relationship when withdrawn from the roller, but which, not Withstanding the spaced relationship of the webs when withdrawn, form a smooth, non-bulging circular looped formation about the roller when the double webs are rolled up on the roller.

This application is a continuation in part of my application, Serial No. 87,284, filed June 25, 1936. In the noted application, the general combination of the roller and shade per se is clearly set forth. In this application it is my object to disclose a double webbed shade having the webs joined together in an improved manner. It is further my object to disclose an improved method of joining the webs and roller in a completed assembly ready for installation.

If two webs of flexible material are joined together by spaced flaps and it is then attempted to roll the two webs in coiled loops about a roller which is round in cross sections, the webs will not lie smoothly and coil in even loops. This is because the outermost of the webs, when rolled up, requires a greater peripheral distance than the inner as a result of which the outer web will buckle.

In the art, prior to my invention, the use of duplex shades was a known development. The joining together of the webs, however, prevented the use of duplex shades if it was desired to roll up the webs on a roller of round cross section. Thus, it will appear in the German Patent No. 382,758 Ausgegeben, October 5, 1923, wherein spaced webs having cut out portions are joined together by fabric strips intermediate the cut out portions a roller, round in cross section was not J proposed. Had such a roller been suggested and had the spacing of the fabric strips and cut out portions been uniform, the double webbed shade could not have been rolled up without buckling.

It is in the appreciation of the necessity of making proper allowance in positioning the interconnecting strips between the Webs which permits the rolling up of the double web on a round roller that my invention is particularly directed.

In this application, certain other improvements in assembly and combination over the combination shown in my copending application, Serial No. 87.284, will be further described and claimed.

Referring to the drawings:

Figure 1 is a plan view of a blank for a double shade cut and ready to assemble.

Figure 2 is a front elevation of the blank shown in Fig. 1 after assembly in a window shade, the

view being shown from the interior of the room looking out the window.

Figure 3 is a sectional view of the shade assembly shown in Fig. 2.

Figure 4 is a rear elevation of the shade or blind assembly shown in Fig. 2 from outside the window looking in. 7

Figure 5 is an enlarged side elevation of the i shade at the start of unrolling from the roller.

Figure 6 is a horizontal section along the lines 6+6 in Fig. 3.

Figure '7 is a vertical section through the assembly shown in Fig. 2 in a normal position.

Figure 8 is a vertical section through the assembly shown in Fig. 7 in an extremely extended position with thecut out portions in the double shade in registry, so as to transmit light through the cut outs.

Since a certain mathematical calculation is necessary in connection with the manner of attaching two flexible webs together so that the two webs will roll smoothly without buckling on the roller a reference to this feature of my invention will first be made.

Supposing that the roller of a shade is one inch in diameter and itis proposed to attach together at spaced intervals two shades and to so space the attaching devices as to permit smooth coiling of the shades on the roller.

The single web of the duplex shade which first forms a complete loop around theroller will occupy a peripheral length of diameter of the roller plus twice the thickness of the web times 3.14159. The next overlying layer or-web will require a greater peripheral length equal to the diameter of the roller plus twice the thickness of the first web plus twice the thickness of the overlying web times 3.14159. -'I'hus, if the two webs are connected together by attaching strips which do not compensate for the variation in peripheral length required for each complete loop by the two webs the outermost web will buckle.

If there are spaced openings in the webs and the attaching strips are formed by tabs cut out on three sides, then the spacings of the cut-out portions of that web which lies outermost in the coiling or looping over the roller must be sufflciently greater than the spacing of the cut-out portions of the innermost web to allow mathematically 2t 3.14159 greater spacing between the cut-outs in the outermost web, in which formula t equals the thickness 01' the web. Thus, if the thickness of the web is .007, the allowance in spacing of the cut-out tabs in the outermost web is .007 times 2 times 3.14159. This allowance, it should be understood, is only proper when the tabs cut out on three sides and articulated on the fourth side, forming the connections between the two webs lie within the space in each web from which the tabs are cut outwhen the double webs are coiled or looped around the roller.

With this theory of proper mathematical spacing explained, I will now describe the further development of my window shade construction, as illustrated in the drawings.

The blank for the double shade is a flexible sheet of material having a short side I and a long side 2 divided along a line 3. The short side, which will comprise the shade visible from within the enclosure looking out the window, is provided with a series of spaced attaching tabs 4 cut out along the bottom and sides, and articulated to the side I along lines of articulation 5. The long side or pull side is also provided with a series of partially cut out tabs 6 articulated to the side 2 along lines of articulation i.

Referring to Fig. 3, it will be observed that when the duplex shade has the several flexible webs thereof connected together by means of overlapping and adhesive juncture of the tabs 4 and 6 that not only are spacers provided, but vanes are formed which induce a natural circulation of air upwardly through the vents. Thus, in Fig. 3 the arrows la indicate the path of air currents through the duplex shade.

In Fig. 2. the spacing tabs are interlapped and secured together either by stapling, stitching, sewing, or adhesive Junction. A shade roller 8 is positioned along the line 5 and the short side I is laid over on the long side 2. Then the spacing tabs are secured together. The duplex shade may be stapled to the roller as indicated at 9 or adhesively secured thereto.

Fig. 6 is a horizontal section showing the spacing tabs secured together. Fig. 7 shows the shade in a normal ventilating position and Fig. 8 shows the shade under extremely downwardly pulled tension with the cut-out ventilating openings in the webs in such registry that light will pass through the openings as indicated at l0.

It should be remembered that in the positioning of the series of cut-out attachment flaps, those on the short or inner web are suitably rial in the shadeand the facilities for assembling the shades.

Of course, the specific rectangular shape of the cutout attachment flaps may be varied to suit particular ideas of artistic design, conforming to the mechanical principle involved in assembling the duplex shades.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A double window shade mounted on a spring tensioned roller, said shade comprising two parallel webs having ventilating openings formeo therein by flaps cut out from the webs said flaps being articulated along parallel lines to said webs,

and flaps of one web being permanently and immovably joined to the corresponding flaps of the other web thereby forming vanes for directing air currents from a ventilating opening in one web to a ventilating opening in the other.

2. A double window shade mounted on a spring tensioned roller, said shade comprising two parallel webs having ventilating openings formed therein by flaps cut out from the webs said flaps being articulated along parallel lines to said webs, and flaps of one web being permanently and immovably joined to the corresponding flaps of the other web thereby forming vanes for directing air currents from a ventilating opening in one web to a ventilating opening in the other, the ventilating openings and flaps in that web positioned outermost as the webs pass around the roller being vertically spaced a greater distance apart than the flaps in the innermost web.

I 3. A double window shade mounted on a spring tensioned roller, said shade comprising two parallel webs having ventilating openings formed therein by flaps cut out from the webs said flaps being articulated along parallel lines-to said webs, and flaps of one web being permanently and immovably joined to the corresponding flaps of the other web thereby forming vanes for directing air currents from a .ventilating opening in one web to a ventilating opening in the other,the ventilating openings and flaps in that web positioned outermost as the webs pass around the, roller beingvertically spaced a greater distance apart than the flaps in the innermost web, the spacing of such greater distance being calculated on the formula 2t 3.14159, where t is equal to the thickness of the webs.

EDWIN L. GRAUEL. 

